1. Field of the Invention
The present invention relates to a half-fitting prevention connector in which a half-fitted condition is positively prevented by a resilient force of a spring member mounted in a housing of at least one of a pair of male and female connectors to be fittingly connected together, and the connector can be positively locked to the mating connector in a fitted condition.
The present application is based on Japanese Patent Application No. Hei. 11-265828, which is incorporated herein by reference.
2. Description of the Related Art
Various half-fitting prevention connectors are already known. For example, Unexamined Japanese Patent Publication No. Hei. 9-55261 discloses a half-fitting prevention connector shown in FIGS. 8 to 13.
As shown in FIG. 8, a male connector 50 includes a hood 51 having a spring receiving chamber 52 therein, and a spring 70, bent into a zigzag shape, is received in this spring receiving chamber 52 so as to be contracted. Guide portions 53a are formed respectively on opposed inner surfaces of a pair of guide walls 53 extending from an inner surface of a top wall of the hood 51.
And besides, in such a half-fitting prevention connector, when canceling the fitted condition, the entire elastic arm 61 needs to be elastically deformed or flexed at a region adjacent to the upstanding proximal end portion thereof, and therefore a large canceling force was required.
Connection terminals are received in terminal receiving chambers in the male connector 50, and connection terminals are also received in terminal receiving chambers in the female connector 60, each of these connection terminals being press-connected to a distal end of a wire. When the two connectors are fittingly connected together, the connection terminals in the male connector are electrically connected respectively to the connection terminals in the female connector.
In the above half-fitting prevention connector in a condition shown in FIG. 9, when the female connector 60 is inserted into the male connector 50, the guide projections 61b, formed respectively on the opposite side edges of the elastic arm 61, slide over the upper surfaces of the guide portions 53a, respectively. At this time, even if the lower end of the elastic arm 61 is pressed down, the guide projections 61b slide over the upper surfaces of the guide portions 53a, respectively, and will not come under the guide portions 53a, respectively, as shown in FIG. 10.
When the guide projections 61b thus slide respectively over the upper surfaces of the guide portions 53a, so that the rear end of the elastic arm 61 is raised as shown in FIG. 11, the retaining projection 61a enters the spring receiving chamber 52 through a communication window 52a formed in an upper portion of the male connector 50. Then, when the female connector 60 is further pushed into the male connector 50, the retaining projection 61a abuts against a front end of the spring 70 to compress the same. At this time, the resilient force of the spring 70 tends to push the female connector 60 back, and therefore when the female connector 60 ceases to be pushed in a half-fitted condition, the female connector 60 is pushed out of the male connector 50.
Then, the guide projections 61b pass the guide portions 53a, respectively, and are retained respectively by these guide portions 53a, so that a completely-fitted condition is achieved as shown in FIG. 13. As a result, the elastic arm 61 is restored into an initial horizontal condition, so that the retaining of the spring 70 by the retaining projection 61a is canceled.
For canceling the fitted condition of the male and female connectors, the rear end of the elastic arm 61 is pressed down to thereby cancel the retaining of the guide projections 61b by the guide portions 53a, as shown in FIG. 14, and the guide projections 61b are disposed under the guide portions 53a, respectively. Then, as the female connector 60 is withdrawn, the guide projections 61b are further pressed down by the lower surfaces of the guide portions 53a, respectively, so that the elastic arm 61 is elastically deformed into a bow-like shape. Then, when the female connector 60 is further withdrawn, the guide projections 61b pass the lower surfaces of the guide portions 53a, respectively, so that the fitted condition of the male and female connectors is canceled.
In the above half-fitting prevention connector, the elastic arm 61 first extends upwardly from the front end of the housing of the female connector 60, and then extends horizontally toward the rear end of the housing. The elastic arm 61 has a generally uniform thickness over the entire length thereof including the upstanding proximal end portion thereof and the horizontal portion thereof, and when canceling the fitted condition, the horizontal portion is flexed or elastically deformed into a bow-like shape.
However, as a result of repeating the connector fitting operation and the connector disengaging operation, the elastic arm 61 was liable to be plastically deformed, with the lower end thereof kept depressed, as shown in FIG. 10. With such deformed elastic arm 61, the locked condition, achieved by the guide portions 53a in the completely-fitted condition, was inadequate, and therefore there was a possibility that the male and female connectors were accidentally disengaged from each other upon application of an external force such as vibrations.
And besides, in such a half-fitting prevention connector, when canceling the fitted condition, the whole of the elastic arm 61 need to be elastically deformed or flexed at a region adjacent to the upstanding proximal end portion thereof, and therefore a large canceling force was required.
With the above problems in view, it is an object of the present invention to provide a half-fitting prevention connector in which a fitted condition can be positively maintained, and a fitted condition-canceling operation can be easily effected.
To achieve the above object, according to the present invention, a transverse cross-sectional area of an interconnecting portion, connecting a lock arm to a housing, is smaller than a transverse cross-sectional area of the lock arm, and the elastic deformation of the lock arm is absorbed only by the elastic deformation of the interconnecting portion so as to prevent the plastic deformation of the lock arm, and the lock arm is urged by the spring member in a direction opposite to the direction of elastic deformation of the lock arm, thereby maintaining a locked condition of the connector housings fitted to each other.
More specifically, first, second and third aspects of the present invention will now be described below.
In the first aspect of the present invention, there is provided a half-fitting prevention connector which comprises a pair of connector housings fittable to each other, a spring member receivable in one of the connector housings, the spring member being operative to prevent a half-fitted condition of the connector housings by a resilient force thereof, an interconnecting portion, and a lock arm elastically-displaceably supported on one of the connector housings through the interconnecting portion, wherein when the connector housings are completely fitted to each other, the spring member urges the lock arm in a direction in which the lock arm retains the other one of the connector housings. Here, a transverse cross-sectional area of the interconnecting portion is smaller than a transverse cross-sectional area of the lock arm so that only the interconnecting portion can be elastically deformed when canceling a fitted condition of the connector housings.
In the second aspect of the present invention, it is preferable that the lock arm extends in a direction in which one of the connector housings is fitted to the other one of the connector housings, wherein the spring member is contractibly held on the lock arm, and has a portion extending in an extending direction of the lock arm. Further, preferably, the half-fitting prevention connector further comprises an engagement portion formed on the other one of the connector housings, the engagement portion retaining the lock arm when the connector housings are completely fitted to each other, and a pressing portion formed on the other one of the connector housings, the pressing portion abutting against the spring member to compress the spring member when the lock arm is elastically displaced by the engagement portion.
In the third aspect of the present invention, it is preferable that the spring member includes a resiliently-bendable portion which is resiliently deformed to urge the lock arm in accordance with an elastic displacement of the lock arm.
Here, the term xe2x80x9ctransverse cross-sectional area of the lock armxe2x80x9d means the area of the cross-section of the lock arm obtained by cutting the lock arm in a direction perpendicular to a direction extending from the free end of the lock arm toward the proximal end thereof connected to the interconnecting portion. The term xe2x80x9ctransverse cross-sectional area of the interconnecting portionxe2x80x9d means the area of the cross-section of the interconnecting portion obtained by cutting the interconnecting portion in a direction perpendicular to a direction extending from one side of the interconnecting portion, connected to the lock arm, toward the other side thereof connected to the housing. The transverse cross-sectional shape of the lock arm, as well as the transverse cross-sectional shape of the interconnecting portion, is not limited, but it is preferred that the maximum value of the transverse cross-sectional area of the interconnecting portion be smaller than the minimum value of the transverse cross-sectional area of the lock arm.
In the half-fitting prevention connector of the above construction, the elastic deformation of the whole lock arm is absorbed only by the elastic deformation of the interconnecting portion, so that the lock arm can be prevented from being plastically deformed. And besides, the lock arm is urged by the spring member in the direction opposite to the direction of elastic displacement of this lock arm, and therefore the entire lock arm will not be elastically deformed, so that the completely-fitted condition can be positively maintained. Furthermore, the increase of the canceling force by the spring member is canceled by increasing the elastic force of the interconnecting portion, and therefore the fitted condition-canceling operation can be effected efficiently.